1. Field of the Invention
This invention relates to flashlights, and more particularly to flashlights that can be used to open and close garage door openers.
2. Description of the Related Art
Small portable flashlights kept in a motor vehicle are relatively common. Typically they are kept in a glove box and only used in an emergency. Because the battery in the flashlight slowly discharges over time and because the flashlight is not tested regularly, the flashlight does not operate when needed.
It is well known that LED bulbs are more energy efficient, have longer lives, and are more mechanically reliable than incandescent bulbs. Because of these benefits, they are commonly used in small, portable lights such as flashlights. LED flashlights found in the prior art generally consist of one or more LED bulbs located inside a housing containing a plurality of batteries. Because LEDs require 5 volts of DC current for optimal illumination, at least three AA or AAA batteries connected in a series are used. As a result, most bright LED flashlights have relatively large housings. When an LED flashlight with a smaller housing is desired, for example with an LED key ring or fob, a single battery may be used but the flashlight illumination will be substantially reduced.
An LED flashlight that overcomes the above drawbacks is disclosed in a U.S. patent application Ser. No. 10/104,895) filed by the inventor on Mar. 22, 2002. Such a flashlight uses a voltage tripler and regulator that enables the use of a single AA or lithium battery. The voltage tripler is a “step-up power component” that raises the battery voltage from 1.5 volts to approximately 5 volts which, is required to sufficiently energize one or more LEDs. Garage door opener transmitters found in the motor vehicle are typically used on a daily basis. When the battery in the transmitter is discharged to a lower level, the transmitter does not operate, thus informing the user that the battery needs to be replaced.
What is needed is a small portable flashlight for use in a motor vehicle that informs the user that the battery is adequately charged for operation.